I saw a demo on how to dynamically change a single control bound to a combobox, something like this:

telerik:StyleManager.Theme="{Binding SelectedValue, ElementName=themesBox}

That's all well and good, but I want to change the theme site-wide via the combobox. So I tried doing this in the MasterPage, again, bound to the ComboBox:

        private void Theme_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            switch (Theme.SelectedItem.ToString())
            {
                case "Office Blue":
                    StyleManager.ApplicationTheme = new Office_BlueTheme();
                    break;
                case "Office Black":
                    StyleManager.ApplicationTheme = new Office_BlackTheme();
                    break;
                case "Office Silver":
                    StyleManager.ApplicationTheme = new Office_SilverTheme();
                    break;
                case "Vista":
                    StyleManager.ApplicationTheme = new VistaTheme();
                    break;
                case "Summer":
                    StyleManager.ApplicationTheme = new SummerTheme();
                    break;
                case "Windows 7":
                    StyleManager.ApplicationTheme = new Windows7Theme();
                    break;
            }
        }
    }

However, nothing changes when select a new setting. Is there something else I need to call in order to make the change "take"?

Hello Todd Davis,

 Regrettably, Silverlight does not allow us to do that. You will have to bind each control that you want to apply a  theme to like so:

That is why the only place where you can set the ApplicationTheme in code-behind for it to have any effect is before InitializeComponent() is called and the controls are created.

All the best,
Yavor Georgiev
the Telerik team